From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3EB97C43334 for ; Thu, 23 Jun 2022 12:09:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231341AbiFWMJA (ORCPT ); Thu, 23 Jun 2022 08:09:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231576AbiFWMI6 (ORCPT ); Thu, 23 Jun 2022 08:08:58 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CA5C4B1FC for ; Thu, 23 Jun 2022 05:08:51 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4LTJs66bLJzkWLt; Thu, 23 Jun 2022 20:07:06 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 23 Jun 2022 20:08:49 +0800 Subject: Re: [PATCH 04/16] mm/huge_memory: use helper touch_pud in huge_pud_set_accessed To: Muchun Song CC: , , , , , References: <20220622170627.19786-1-linmiaohe@huawei.com> <20220622170627.19786-5-linmiaohe@huawei.com> From: Miaohe Lin Message-ID: <80a029bc-3613-1150-cbd3-134d340b3973@huawei.com> Date: Thu, 23 Jun 2022 20:08:47 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/6/23 14:42, Muchun Song wrote: > On Thu, Jun 23, 2022 at 01:06:15AM +0800, Miaohe Lin wrote: >> Use helper touch_pud to set pud accessed to simplify the code and improve >> the readability. No functional change intended. >> >> Signed-off-by: Miaohe Lin >> --- >> mm/huge_memory.c | 14 ++++---------- >> 1 file changed, 4 insertions(+), 10 deletions(-) >> >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index a26580da8011..a0c0e4bf9c1e 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -1281,21 +1281,15 @@ int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm, >> >> void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud) >> { >> - pud_t entry; >> - unsigned long haddr; >> - bool write = vmf->flags & FAULT_FLAG_WRITE; >> + int flags = 0; >> >> vmf->ptl = pud_lock(vmf->vma->vm_mm, vmf->pud); >> if (unlikely(!pud_same(*vmf->pud, orig_pud))) >> goto unlock; >> >> - entry = pud_mkyoung(orig_pud); >> - if (write) >> - entry = pud_mkdirty(entry); >> - haddr = vmf->address & HPAGE_PUD_MASK; >> - if (pudp_set_access_flags(vmf->vma, haddr, vmf->pud, entry, write)) >> - update_mmu_cache_pud(vmf->vma, vmf->address, vmf->pud); >> - >> + if (vmf->flags & FAULT_FLAG_WRITE) >> + flags = FOLL_WRITE; > > FOLL_* flags are used for follow_page(). But huge_pud_set_accessed() is used in mm fault > path. It is a little weird to me to use FOLL_WRITE here. I suggest replace the last > parameter of touch_pud() to "bool writable", then passing "vmf->flags & FAULT_FLAG_WRITE" > to it instead of converting from FAULT_FLAG* flag to FOLL* flag. Sounds good. Thanks! > > Thanks. > >> + touch_pud(vmf->vma, vmf->address, vmf->pud, flags); >> unlock: >> spin_unlock(vmf->ptl); >> } >> -- >> 2.23.0 >> >> > . >